A study (ID# 1118) from Israel that is being presented as an oral presentation this morning at SLEEP 2008 shows that teens may have improved attention and concentration when their school start time is delayed.

The study involved 47 eighth-grade students from two classes. A control group began school at the regular time (7:30 a.m.) each day for two weeks. The experimental group began the schoolday one hour later (8:30 a.m.) during week one and then at the usual time during week two.

During the first week, students in the experimental group woke up an average of 51 minutes later each morning than students in the control group. Bedtime remained the same.

The experimental group performed better than the control group on two cognitive tests that were performed on the fifth day of the first week. They had a better overall attention score on a computerized test and made fewer mistakes on a paper-and-pencil test.

A study from the University of Pittsburgh (ID# 0195) that is being presented as an oral presentation this morning at SLEEP 2008 takes a deeper look at the relationship between short sleep duration and obesity. The study concludes that a core aspect of this association may be reduced amounts of rapid eye movement (REM) sleep.

The study involved 335 children and teens between the ages of seven and 17 years. Sleep was measured by polysomnography for three consecutive nights. Compared with normal-weight children, overweight children slept about 22 minutes less per night.

Overweight children also had shorter REM sleep periods, lower REM activity and density, and longer latency to the first REM period. After adjusting for other factors, one hour less of REM sleep increased the risk of being overweight by about three times, while one hour less of total sleep increased the odds of overweight by about two times.

Two studies being presented as oral presentation this morning at SLEEP 2008 address the relationship between sleep and suicidal behavior in children.

A study (ID# 0194) of 450 boys and 348 girls examined how children may be affected when a parent has a history of chronic insomnia. The children in the study had an average age of 14.4 years.

Teens with a parental history of chronic insomnia were much more likely to report having suicidal thoughts than teens without a parental history of insomnia (16.7% vs. 5.3%); they also were more likely to have a suicide plan (9.5% vs. 1.5%) and to have attempted suicide (9.5% vs. 1.7%).

Another study (ID# 0180) involved 303 children and teens with bipolar disorder and unipolar disorder during depressive episodes. The children in the study had an average age of 12.8 years.

Results show that 83.8 percent of the children had sleep disturbances. The presence of sleep complaints showed a significant association with suicidal behavior. Children with bipolar disorder were more likely than children with unipolar disorder to report suicidal behaviors with sleep complaints, classified as suicidal thoughts (58% vs. 35.6%), desire to die (58% vs. 31.5%), suicide plans (55.5% vs. 22.3%), and suicide attempt (40.7% vs. 19.8%).The SLEEP 2008 abstract book is available online at http://www.journalsleep.org/PDF/AbstractBook2008.pdf.

A study (ID# 0187) being presented as an oral presentation this morning at SLEEP 2008 shows that sleep disordered breathing of any level of severity is associated with increased levels of blood pressure in children.

The Australian study involved 88 children between the ages of seven and 13 years. Twenty of these children were non-snoring controls who were recruited from the community.

Mean arterial pressure (MAP) was lower in the control group both before falling asleep and during sleep. MAP was elevated during sleep in children with either primary snoring, mild obstructive sleep apnea (OSA), or moderate to severe OSA.